Mailman 3 May 2019 - Matplotlib-users

Constant failed import
by Pierig Havez-Bodivit June 18, 2019

June 18, 2019

Hi, my name is Pierig, I’m a French student, I use python for my study but I’ve got issue with your library. I’m running it on PyCharm and Pyzo on MacOSX and while I can import your library, there's no way of using any of the module, such as : plt.figure() or plt.plot() while other libraries like numpy work. I’ve got this message: I really need your library to work, can you help me with that? Sincerely yours Pierig

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plot
by Partha Sinha May 31, 2019

May 31, 2019

I want help on graph I need to plot numbers one by one (lets say after interval of 5 sec) but all in the same graph. How to do ? My code is below import time import matplotlib.pyplot as plt import numpy as np from random import randint i = 1 numbers = [0]*5 while i < 5: numbers[i] = randint(0,100) plt.plot(np.arange(1,6),numbers, 'o') i += 1 matplotlib.pyplot.draw() time.sleep(5)

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live plot
by Rached Zakhama May 29, 2019

May 29, 2019

Hi, I was trying to make a live plot with tkinter where I can see the data updating live in a for loop. I used a tkinter window to plot the matplotlib figure and I added a button. The problem is that I can't make the button work during the for loop. My example is : ############################## # imports import numpy as np from time import sleep import matplotlib matplotlib.use("TkAgg") from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg from matplotlib.figure import Figure from matplotlib.pyplot import pause import tkinter as tk fenetre = tk.Tk() # update function , called whenever the user hit the button : changes the plot line color def update(): n=np.random.randint(4) colors=['b','g','r','c'] l.set_color(colors[n]) canvas.show() # tkinter button, changes the line color bouton = tk.Button(fenetre, text="change color", command=update) bouton.pack() # create random data x=np.array([i for i in range(10)]) y=np.random.randn(10) # create matplotlib figure and plot fig=Figure(figsize=(5,5)) ax=fig.add_subplot(111) l,=ax.plot(x,y) # put the figure in the tkinter window canvas=FigureCanvasTkAgg(fig,fenetre) canvas.show() canvas.get_tk_widget().pack(side=tk.TOP,fill=tk.BOTH, expand=True) # add the toolbar toolbar= NavigationToolbar2TkAgg(canvas,fenetre) toolbar.update() canvas._tkcanvas.pack(side=tk.TOP,fill=tk.BOTH, expand=True) # update random data every 2 seconds for i in range(15): sleep(2) y=np.random.randn(10) l.set_ydata(y) canvas.show() tk.mainloop() ###################### I am trying to see a plot random data changing on the screen every 2 seconds and change its color whenever I hit the button. It doesn't work since apparently Python doesn't execute the button command before finishing the loop. Do you have any suggestions. Waiting hopefully for your replay. Best regards. ___________________________________________________________________ Rached ZAKHAMA Bureau 2B1 33 Thales Research & Technology III-V lab, 91120 Palaiseau,France tel: +33(0)169416021 +33(0)658787715 <callto:+33%280%29169416021> ___________________________________________________________________

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Autoscaling Date Locator with minor ticks?
by Akkana Peck May 26, 2019

May 26, 2019

Is there any way to get AutoDateLocator to handle minor ticks as well as major ones? For instance, if I have a plot spanning a few days, I'd like to be able to show the date as a label and major tick, but show minor ticks for hours, or one minor tick every six hours, whatever is sensible depending on the scale. Or on a plot spanning a few years, show labels for each year, but with 12 minor ticks showing months. It seems like AutoDateLocator only draws major ticks. I can write a custom date locator that handles the minor ticks nicely, but then I don't get the nice auto-scaling of AutoDateLocator, and if I plot a larger or smaller date range, my labels and ticks become too crowded or too sparse. I tried setting both major and minor locators to AutoDateLocators: ax.xaxis.set_major_locator(AutoDateLocator()) ax.xaxis.set_minor_locator(AutoDateLocator()) and similarly with set_*_formatter(), but that just gave me smeary-looking double-printed major labels and ticks. Maybe I need to write a custom smart locator that reproduces AutoDateLocator's auto-scaling while also handling ticks. But before I dive into that, I thought I'd ask; I can't be the only person who needs more precise ticks and labeling than AutoDateLocator provides. Thanks! ...Akkana

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Get color from legend for errorbar plots
by Bruno Pagani May 23, 2019

May 23, 2019

Hi, I’ve stumbled upon this very exact issue, for which there is no posted answer: https://stackoverflow.com/questions/26573864/matplotlib-get-errorbar-color-… Does anyone have an idea? Regards, Bruno

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scatter plot with data coord sized glyphs
by Heiland, Randy May 22, 2019

May 22, 2019

Hello, Is it possible to specify scatter plot glyph sizes - specifically, circles and, e.g., radii, in data coords, rather than “marker size” of “points**2”? thanks, Randy

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Matplotlib plots display as blank in interactive mode with no error messages - (one) Solution
by FilipPersson May 19, 2019

May 19, 2019

I spent several hours googling and trying myself to change my code to fix this. No luck in googling and the fact that there was a kind of doing brain surgery on Matplotlib by uninstall, re-install and update and change backend library for a similar but not quite the same problem made me think that I should post the solution somewhere since it was almost impossible to spot. If you get plots like this: <http://matplotlib.1069221.n5.nabble.com/file/t5236/Blank_plot.png> Which, as you see gives no error output - not even when clicking on the graph. Actually, nothing at all happens when clicking on the graph. Interactivity is lost. It could be a LaTeX problem causing it! The reason for the blank plot was that I had used a LaTeX escape character for the value 0 when creating nice labels for the x axis. Apparently, using '$\0$' to write the number zero in LaTeX makes the plots blank and kills the interactivity. Restarting the kernel did no good. If I instead write '$0$' as a label, everything works fine again. My environment is Mac OSX 10.13.6, Matplotlib 3.0.2, Python 3.7.1, running in Jupyter (notebook server version 5.7.4, IPython 7.2.0) in Safari Version 12.0 (13606.2.11). If you want to see my code, please request it and then I will post it. -- Sent from: http://matplotlib.1069221.n5.nabble.com/matplotlib-users-f3.html

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Re: [Matplotlib-users] Convolution integral export as animation
by Thomas Caswell May 19, 2019

May 19, 2019

Try 'reply-all' instead? Yes, that is controlled by the fps kwarg to `anim.save`. Glad it is working! Tom On Sun, May 19, 2019 at 6:23 PM Erdem <farukerdemoncel(a)gmail.com> wrote: > My reply does not show in the mail list. I have no idea why this happened > but I simply use Gmail to reply. I used to use Gnus message reader with > Emacs but I think it is not installed for now. > > Thanks now it works as expected! > > Is there a way to slow down animation a bit. > > Erdem > > > Thomas Caswell <tcaswell(a)gmail.com>, 20 May 2019 Pzt, 01:05 tarihinde > şunu yazdı: > >> Please don't drop the mailing list from the replies. >> >> Ah, I ran it by invoking the script in an IPython session where >> `plt.ion()` has been called and `plt.show()` in non-blocking. If I run it >> as as script I see what you descirbe! >> >> Removing the `plt.show()` calls from inside of the re-draw function >> allows it to run end-to-end and write out the animation. >> >> Tom >> >> On Sun, May 19, 2019 at 5:59 PM Erdem <farukerdemoncel(a)gmail.com> wrote: >> >>> Thank you very much. >>> >>> My operating system is Ubuntu 18.04 LTS 64 bit. I've set up a virtual >>> python environment and to activate I use this command. >>> >>> $ . venv/bin/activate >>> >>> I've saved source file as convolution py. To run the source code I use >>> this command >>> >>> $ python convolution.py >>> >>> But rather than an animation I see only a plot of integral at t0=-2.00 >>> >>> [image: convolution.png] >>> >>> I wait some time and nothing happens. I've also tried to close window a >>> few times and the result is same. >>> >>> Since you may be able to get an mp4 file of the animation may it be >>> because of some codecs are missing or may be a bug? >>> >>> Erdem >>> >>> Thomas Caswell <tcaswell(a)gmail.com>, 20 May 2019 Pzt, 00:17 tarihinde >>> şunu yazdı: >>> >>>> Erdem, >>>> >>>> I do not understand your question. If I run that code I do get an mp4 >>>> file of the animation. >>>> >>>> Tom >>>> >>>> >>>> On Sat, May 18, 2019 at 6:05 PM Erdem <farukerdemoncel(a)gmail.com> >>>> wrote: >>>> >>>>> This example is taken from a tutorial >>>>> <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-…> related >>>>> to convolution integral. >>>>> >>>>> I would like to export this example as animation in mp4 format. So >>>>> far, the code looks like this : >>>>> >>>>> import scipy.integrateimport numpy as npimport matplotlib.pyplot as pltimport matplotlib.animation as animation >>>>> def showConvolution(t0,f1, f2): >>>>> # Calculate the overall convolution result using Simpson integration >>>>> convolution = np.zeros(len(t)) >>>>> for n, t_ in enumerate(t): >>>>> prod = lambda tau: f1(tau) * f2(t_-tau) >>>>> convolution[n] = scipy.integrate.simps(prod(t), t) >>>>> >>>>> # Create the shifted and flipped function >>>>> f_shift = lambda t: f2(t0-t) >>>>> prod = lambda tau: f1(tau) * f2(t0-tau) >>>>> >>>>> # Plot the curves >>>>> plt.gcf().clear() # il >>>>> >>>>> plt.subplot(211) >>>>> plt.gca().set_ymargin(0.05) # il >>>>> plt.plot(t, f1(t), label=r'$f_1(\tau)$') >>>>> plt.plot(t, f_shift(t), label=r'$f_2(t_0-\tau)$') >>>>> plt.fill(t, prod(t), color='r', alpha=0.5, edgecolor='black', hatch='//') # il >>>>> plt.plot(t, prod(t), 'r-', label=r'$f_1(\tau)f_2(t_0-\tau)$') >>>>> plt.grid(True); plt.xlabel(r'$\tau$'); plt.ylabel(r'$x(\tau)$') # il >>>>> plt.legend(fontsize=10) # il >>>>> plt.text(-4, 0.6, '$t_0=%.2f$' % t0, bbox=dict(fc='white')) # il >>>>> >>>>> # plot the convolution curve >>>>> plt.subplot(212) >>>>> plt.gca().set_ymargin(0.05) # il >>>>> plt.plot(t, convolution, label='$(f_1*f_2)(t)$') >>>>> >>>>> # recalculate the value of the convolution integral at the current time-shift t0 >>>>> current_value = scipy.integrate.simps(prod(t), t) >>>>> plt.plot(t0, current_value, 'ro') # plot the point >>>>> plt.grid(True); plt.xlabel('$t$'); plt.ylabel('$(f_1*f_2)(t)$') # il >>>>> plt.legend(fontsize=10) # il >>>>> plt.show() # il >>>>> Fs = 50 # our sampling frequency for the plotting >>>>> T = 5 # the time range we are interested in >>>>> t = np.arange(-T, T, 1/Fs) # the time samples >>>>> f1 = lambda t: np.maximum(0, 1-abs(t)) >>>>> f2 = lambda t: (t>0) * np.exp(-2*t) >>>>> >>>>> t0 = np.arange(-2.0,2.0, 0.05) >>>>> >>>>> fig = plt.figure(figsize=(8,3)) >>>>> anim = animation.FuncAnimation(fig, showConvolution, frames=t0, fargs=(f1,f2),interval=80) >>>>> >>>>> anim.save('animation.mp4', fps=30) # fps = frames per second >>>>> >>>>> plt.show() >>>>> >>>>> >>>>> When I run the program I see the output of see the output of >>>>> convolution integral at t0 = -0.20. >>>>> >>>>> [image: convolution.png] >>>>> >>>>> Is there a way to change t0 so that I'd like to able to save it as >>>>> animation as in the tutorial >>>>> <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-…> In >>>>> the example t0 decreases from -2.0 to -1.95 etc the green curve is shifted >>>>> right, and the area between curves, product increases. In the tutorial >>>>> there is an html animation and I would like to save as mp4 file. >>>>> >>>>> I've also added source code as an attachment. >>>>> _______________________________________________ >>>>> Matplotlib-users mailing list >>>>> Matplotlib-users(a)python.org >>>>> https://mail.python.org/mailman/listinfo/matplotlib-users >>>>> >>>> >>>> >>>> -- >>>> Thomas Caswell >>>> tcaswell(a)gmail.com >>>> >>> >> >> -- >> Thomas Caswell >> tcaswell(a)gmail.com >> > -- Thomas Caswell tcaswell(a)gmail.com

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Re: [Matplotlib-users] Convolution integral export as animation
by Thomas Caswell May 19, 2019

May 19, 2019

Please don't drop the mailing list from the replies. Ah, I ran it by invoking the script in an IPython session where `plt.ion()` has been called and `plt.show()` in non-blocking. If I run it as as script I see what you descirbe! Removing the `plt.show()` calls from inside of the re-draw function allows it to run end-to-end and write out the animation. Tom On Sun, May 19, 2019 at 5:59 PM Erdem <farukerdemoncel(a)gmail.com> wrote: > Thank you very much. > > My operating system is Ubuntu 18.04 LTS 64 bit. I've set up a virtual > python environment and to activate I use this command. > > $ . venv/bin/activate > > I've saved source file as convolution py. To run the source code I use > this command > > $ python convolution.py > > But rather than an animation I see only a plot of integral at t0=-2.00 > > [image: convolution.png] > > I wait some time and nothing happens. I've also tried to close window a > few times and the result is same. > > Since you may be able to get an mp4 file of the animation may it be > because of some codecs are missing or may be a bug? > > Erdem > > Thomas Caswell <tcaswell(a)gmail.com>, 20 May 2019 Pzt, 00:17 tarihinde > şunu yazdı: > >> Erdem, >> >> I do not understand your question. If I run that code I do get an mp4 >> file of the animation. >> >> Tom >> >> >> On Sat, May 18, 2019 at 6:05 PM Erdem <farukerdemoncel(a)gmail.com> wrote: >> >>> This example is taken from a tutorial >>> <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-…> related >>> to convolution integral. >>> >>> I would like to export this example as animation in mp4 format. So far, >>> the code looks like this : >>> >>> import scipy.integrateimport numpy as npimport matplotlib.pyplot as pltimport matplotlib.animation as animation >>> def showConvolution(t0,f1, f2): >>> # Calculate the overall convolution result using Simpson integration >>> convolution = np.zeros(len(t)) >>> for n, t_ in enumerate(t): >>> prod = lambda tau: f1(tau) * f2(t_-tau) >>> convolution[n] = scipy.integrate.simps(prod(t), t) >>> >>> # Create the shifted and flipped function >>> f_shift = lambda t: f2(t0-t) >>> prod = lambda tau: f1(tau) * f2(t0-tau) >>> >>> # Plot the curves >>> plt.gcf().clear() # il >>> >>> plt.subplot(211) >>> plt.gca().set_ymargin(0.05) # il >>> plt.plot(t, f1(t), label=r'$f_1(\tau)$') >>> plt.plot(t, f_shift(t), label=r'$f_2(t_0-\tau)$') >>> plt.fill(t, prod(t), color='r', alpha=0.5, edgecolor='black', hatch='//') # il >>> plt.plot(t, prod(t), 'r-', label=r'$f_1(\tau)f_2(t_0-\tau)$') >>> plt.grid(True); plt.xlabel(r'$\tau$'); plt.ylabel(r'$x(\tau)$') # il >>> plt.legend(fontsize=10) # il >>> plt.text(-4, 0.6, '$t_0=%.2f$' % t0, bbox=dict(fc='white')) # il >>> >>> # plot the convolution curve >>> plt.subplot(212) >>> plt.gca().set_ymargin(0.05) # il >>> plt.plot(t, convolution, label='$(f_1*f_2)(t)$') >>> >>> # recalculate the value of the convolution integral at the current time-shift t0 >>> current_value = scipy.integrate.simps(prod(t), t) >>> plt.plot(t0, current_value, 'ro') # plot the point >>> plt.grid(True); plt.xlabel('$t$'); plt.ylabel('$(f_1*f_2)(t)$') # il >>> plt.legend(fontsize=10) # il >>> plt.show() # il >>> Fs = 50 # our sampling frequency for the plotting >>> T = 5 # the time range we are interested in >>> t = np.arange(-T, T, 1/Fs) # the time samples >>> f1 = lambda t: np.maximum(0, 1-abs(t)) >>> f2 = lambda t: (t>0) * np.exp(-2*t) >>> >>> t0 = np.arange(-2.0,2.0, 0.05) >>> >>> fig = plt.figure(figsize=(8,3)) >>> anim = animation.FuncAnimation(fig, showConvolution, frames=t0, fargs=(f1,f2),interval=80) >>> >>> anim.save('animation.mp4', fps=30) # fps = frames per second >>> >>> plt.show() >>> >>> >>> When I run the program I see the output of see the output of convolution >>> integral at t0 = -0.20. >>> >>> [image: convolution.png] >>> >>> Is there a way to change t0 so that I'd like to able to save it as >>> animation as in the tutorial >>> <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-…> In >>> the example t0 decreases from -2.0 to -1.95 etc the green curve is shifted >>> right, and the area between curves, product increases. In the tutorial >>> there is an html animation and I would like to save as mp4 file. >>> >>> I've also added source code as an attachment. >>> _______________________________________________ >>> Matplotlib-users mailing list >>> Matplotlib-users(a)python.org >>> https://mail.python.org/mailman/listinfo/matplotlib-users >>> >> >> >> -- >> Thomas Caswell >> tcaswell(a)gmail.com >> > -- Thomas Caswell tcaswell(a)gmail.com

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Convolution integral export as animation
by Erdem May 19, 2019

May 19, 2019

This example is taken from a tutorial <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-…> related to convolution integral. I would like to export this example as animation in mp4 format. So far, the code looks like this : import scipy.integrateimport numpy as npimport matplotlib.pyplot as pltimport matplotlib.animation as animation def showConvolution(t0,f1, f2): # Calculate the overall convolution result using Simpson integration convolution = np.zeros(len(t)) for n, t_ in enumerate(t): prod = lambda tau: f1(tau) * f2(t_-tau) convolution[n] = scipy.integrate.simps(prod(t), t) # Create the shifted and flipped function f_shift = lambda t: f2(t0-t) prod = lambda tau: f1(tau) * f2(t0-tau) # Plot the curves plt.gcf().clear() # il plt.subplot(211) plt.gca().set_ymargin(0.05) # il plt.plot(t, f1(t), label=r'$f_1(\tau)$') plt.plot(t, f_shift(t), label=r'$f_2(t_0-\tau)$') plt.fill(t, prod(t), color='r', alpha=0.5, edgecolor='black', hatch='//') # il plt.plot(t, prod(t), 'r-', label=r'$f_1(\tau)f_2(t_0-\tau)$') plt.grid(True); plt.xlabel(r'$\tau$'); plt.ylabel(r'$x(\tau)$') # il plt.legend(fontsize=10) # il plt.text(-4, 0.6, '$t_0=%.2f$' % t0, bbox=dict(fc='white')) # il # plot the convolution curve plt.subplot(212) plt.gca().set_ymargin(0.05) # il plt.plot(t, convolution, label='$(f_1*f_2)(t)$') # recalculate the value of the convolution integral at the current time-shift t0 current_value = scipy.integrate.simps(prod(t), t) plt.plot(t0, current_value, 'ro') # plot the point plt.grid(True); plt.xlabel('$t$'); plt.ylabel('$(f_1*f_2)(t)$') # il plt.legend(fontsize=10) # il plt.show() # il Fs = 50 # our sampling frequency for the plotting T = 5 # the time range we are interested in t = np.arange(-T, T, 1/Fs) # the time samples f1 = lambda t: np.maximum(0, 1-abs(t)) f2 = lambda t: (t>0) * np.exp(-2*t) t0 = np.arange(-2.0,2.0, 0.05) fig = plt.figure(figsize=(8,3)) anim = animation.FuncAnimation(fig, showConvolution, frames=t0, fargs=(f1,f2),interval=80) anim.save('animation.mp4', fps=30) # fps = frames per second plt.show() When I run the program I see the output of see the output of convolution integral at t0 = -0.20. [image: convolution.png] Is there a way to change t0 so that I'd like to able to save it as animation as in the tutorial <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-…> In the example t0 decreases from -2.0 to -1.95 etc the green curve is shifted right, and the area between curves, product increases. In the tutorial there is an html animation and I would like to save as mp4 file. I've also added source code as an attachment.

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